Showing papers by "Timothy O. Randhir published in 2015"

Effect of climate and land cover changes on watershed runoff: A multivariate assessment for storm water management

Abstract: Impact of climate change and land use on watershed runoff involves multiattribute ecohydrologic interactions. This information is critical to development of comprehensive storm water management policies. Watersheds in the continental United States have diverse temperatures and precipitation regimes and varying hydrogeomorphic features that influence runoff. This study investigates watershed-scale runoff using statistical modeling for storm water policy optimization. Multivariate statistical modeling show that vegetative activity, annual evaporation, precipitation, temperature, and soil moisture significantly influenced watershed runoff. Soil moisture has a strong influence on runoff with each percent increase causing 5% increase in runoff. Nonlinear modeling with quadratic and interaction effects shows a significant interaction between soil moisture and other climatic variables in influencing annual runoff patterns. Changes in climate affect ecohydrologic characters by altering available soil moisture, evaporation, precipitation patterns, and runoff. Optimization of green infrastructure design can be a successful management tool for runoff with an understanding that changes to multiple attributes in ecohydrologic variables affect runoff. Multi-attribute-based green infrastructure and incentive policies can result in comprehensive storm water policies that incorporate climatic and ecohydrologic conditions of watershed systems.

Rhinos in the Parks: An Island-Wide Survey of the Last Wild Population of the Sumatran Rhinoceros.

Abstract: In the 200 years since the Sumatran rhinoceros was first scientifically described (Fisher 1814), the range of the species has contracted from a broad region in Southeast Asia to three areas on the island of Sumatra and one in Kalimantan, Indonesia. Assessing population and spatial distribution of this very rare species is challenging because of their elusiveness and very low population number. Using an occupancy model with spatial dependency, we assessed the fraction of the total landscape occupied by Sumatran rhinos over a 30,345-km2 survey area and the effects of covariates in the areas where they are known to occur. In the Leuser Landscape (surveyed in 2007), the model averaging result of conditional occupancy estimate was ψ^(SE[ψ^])=0.151(0.109) or 2,371.47 km2, and the model averaging result of replicated level detection probability p^(SE[p^])=0.252(0.267); in Way Kambas National Park—2008: ψ^(SE[ψ^])=0.468(0.165) or 634.18 km2, and p^(SE[p^])=0.138(0.571); and in Bukit Barisan Selatan National Park—2010: ψ^(SE[ψ^])=0.322(0.049) or 819.67 km2, and p^(SE[p^])=0.365(0.42). In the Leuser Landscape, rhino occurrence was positively associated with primary dry land forest and rivers, and negatively associated with the presence of a road. In Way Kambas, occurrence was negatively associated with the presence of a road. In Bukit Barisan Selatan, occurrence was negatively associated with presence of primary dryland forest and rivers. Using the probabilities of site occupancy, we developed spatially explicit maps that can be used to outline intensive protection zones for in-situ conservation efforts, and provide a detailed assessment of conserving Sumatran rhinos in the wild. We summarize our core recommendation in four points: consolidate small population, strong protection, determine the percentage of breeding females, and recognize the cost of doing nothing. To reduce the probability of poaching, here we present only the randomized location of site level occupancy in our result while retaining the overall estimation of occupancy for a given area.

Watershed Management - Issues and Approaches

Abstract: Watershed management is an integrated approach that evaluates system-wide implications of natural resource problems. It has received considerable attention among communities and resource managers as an appropriate approach to deal with complex problems. Problem-solving is an important aspect of watersheds that involves diagnosis, assessment, solution, and implementation issues that often mean processing an enormous amount of information. A typical problem requires compilation of information from a variety of sources and is time consuming. This book will use a problem-based approach to present information on each problem facing watersheds. The subject area derives from a variety of disciplines and experiences and is presented clear and systematically throughout for easy reading and understanding. The problems covered in the book are major ones facing watersheds through the globe. The first chapter introduces principles of watershed management and is followed by chapters that are problem specific. Each problem is dealt with systematically with introduction, analysis, strategies, and further references. Watershed Management provides a valuable reference to professionals, students, scientists, and common citizens who are interested in learning about the variety of problems and approaches in watershed management.

Correction: Rhinos in the Parks: An Island-Wide Survey of the Last Wild Population of the Sumatran Rhinoceros.

Abstract: In the 200 years since the Sumatran rhinoceros was first scientifically described (Fisher 1814), the range of the species has contracted from a broad region in Southeast Asia to three areas on the island of Sumatra and one in Kalimantan, Indonesia. Assessing population and spatial distribution of this very rare species is challenging because of their elusiveness and very low population number. Using an occupancy model with spatial dependency, we assessed the fraction of the total landscape occupied by Sumatran rhinos over a 30,345-km 2 survey area and the effects of covariates in the areas where they are known to occur. In the Leuser Landscape (surveyed in 2007), the model averaging result of conditional occupancy

Risk Perceptions and Adaptation to Climate Variability: Survey Evidence from Maple Syrup Farmers

Abstract: There is a rising concern that climate change is affecting maple syrup production in North America. Against this backdrop, we have conducted a survey to better understand the risk perceptions and vulnerability of maple farmers regarding the impact of climate change on maple syrup production. Survey responses indicate that a majority of maple farmers are concerned that anomalous variations in temperature relating to climate change have already affected the length and time of the tapping season. Many of them believe that the quantity and quality of maple sap are adversely affected as a result of climate change. About one third of our sample respondents have missed the first sap flow of the season in recent years which usually produces the highest quality maple syrup. Our study also investigates risk averting behavior in response to climate induced risk faced by maple farmers. While we find relatively lower demand for risk information (reliable long range weather forecasting) and for formal crop insurance program, a majority of respondents would prefer diversifying their income earning activities in response to this risk. We discuss policy implications of our findings.